op basel



Patented Nov. 2 2, 1927.

UNITED STATES PATENT OFFICE.

HEINRICH HOZ, WALTER- BEBHOULLI, AND ARTHUR LINK, OIBASEL, SWITZERLAND, ASSIGNORS TO THE FIRE J. B. GEIGY S. A O! BASEL, SWITZERLAND.

rnoonss 01'' Drama am) ram'rmo ACE'IYL OELLULOBE.

1W0 Drawing. Original application filed larch 5, 1924, Serial No. 897,145, and in Germany larch 31,

1923. Divided and this application filed July 22, 1925. Serial Io. 45,408.

This application is divisional of application Ser. No. 697 ,145.

Hitherto known processes of dyeing actylcellulose have injurious eflects on the fibre. Through additions to the dyeing bath or through a convenient method of previous treatment mostly by the employment of saponiiying alkalis or of organic solvents, or through too high a temperature in dyeing, the acetyl-cellulose is prejudicially altere so that its valuable qualities are reduced or entirely destroyed.

It has now been discovered that with a large number of dyestufis, which by themselves have only a weak aflinity for acct cellulose, these disadvantages can be avoi ed in producing the dyeing and printing of acetyl-cellulose in the presence of aryl-carboxylic acid anions. This effect can be obtained by the addition to a dye bath or'printing paste of aryl-carboxylicacid compounds of any kind, in the form of free acids or salts, the dyestuffs being thus brought into .a form in which they are taken up by the fibre at a relatively'low temperature, which is quite harmless to the acetyl-cellulose. In this case, it may be advantageous to add protective colloids such as glue, elatine, glucose, bast soap or the like, particularly with dyes which show a tendency to precipitate on the addition of or anic acids.

Instead of ad 7 ing) aryl-carboxylic acid compounds to a dye ath or printing paste the acetyl-cellulose can be previously treated with such compounds alone and afterwards,

if necessary with the addition of protective colloids, dye or printed as usual with a fresh or old bath, the essential feature-being always the production of the dyeing and printing in the presence of aryl-carboxylic acid 81110118. v

In these r ts, salycilie acids and their derivatives su ituted-by one or more oxy-, alkyl-, chloro-or nitro-groups may be suitable for the present invention.

1. acetyl-ce The particular working method is shown by the following examples. 1

Ewample 1.2% of auramine having the formula 4% of gelatine and 2% of benzoic acid are usedin the same way as Example 1. Ratio of fibre to solution 1:60.

E'wample 3.The acetyl-cellulose is treate for an hour. at to C. with a solution of 2% of 2-oxy-isonaphthalic acid in water, the ratio of fibre to solution being 1 60.

'After wringing out, it is dyed in a fresh bath containing in solution 4% of gelatin and t 2% of crystallized malachite een for halfan-hour at a temperature 0 45 to 50 C. v

1 Ratio of fibre to solution 1 :60.

The same'compounds can also addition to printing pastes;

Whit we claimfim-a I rocess or e" and printing fiulose, producing the be used as dyeing and printing of finished :iotyLcellnthen treating finished acetyl cellulose with lose with coloring matters in the presence of the mass thus prepared.

aryl-carboxylic acid anions.v In witness whereof we have hereunto l0 2. A process for dyeing and printing signed our names this 10th day of July, 1925. 5 acetyl-cellulose, consisting in adding to the HEINRICH HOZ.

dyeing and printing mass :1 compound con- WALTER BERNOULLI.

taining aryl-carboxylic acid anions and in i LINK. 

